deno test should run jsdoc example code

[ry]

As cargo test does. This makes example code way more robust.

We’d need a way to extract all the examples - but now that we have deno doc - this should be not too difficult.

[akshatagarwl]

@ry Can I work on this?

[ry]

@humancalico Sure go for it. I'd start by defining an internal rust API for getting all of the code examples given a script's URL. Once that's working and tested, it should be just a bit more work to hook it into "deno test".

[akshatagarwl]

@ry Should this be implemented directly for deno test or as a part of deno doc --test first? Kinda like Rust does it with rustdoc --test

[iykekings]

@humancalico and @ry what is the progress on this? I'm interested on working on it if nobody is on it.

[akshatagarwl]

@iykekings I got sidetracked. Go ahead if you want to.😊

[bartlomieju]

For posterity: we now support type-checking docstrings, running examples is still a TODO that @caspervonb was looking into

[waldyrious]

we now support type-checking docstrings

For the record, that was done in #10521, and later #11421 extended that to also type-check code blocks within markdown files.

[linus]

I have published a module which could potentially handle this: https://deno.land/x/[email protected]

A couple of improvements I would like to make, but not sure how:

1. It runs all tests using indirect eval in a Worker. It would feel better to implement this using something similar to Node's vm.runInContext.
2. Currently, it doesn't automatically discover and run the @example, it needs to be wrapped in Deno.test((t) => doctest(t, file)) in a file under test. Any pointers on hooking it into deno test would be appreciated.